The present invention relates to a semiconductor wafer accommodating jig, a handling method and a production system
One of the serious issues in the processes for advanced semiconductor devices is that an adhesion of fine dusts on the semiconductor device might provide a fatal damage to the product, resulting in a drop of the yield, for which reason automation of the production line is made by taking into account of separation of the line from dusts or any for generating dusts. Actually, however, it is difficult to realize automatic maintenance and automatic trouble shooting systems, even human is the source for generating dusts.
To settle the above problems, it is effective to isolate the semiconductor device from atmosphere. In view of this, it was proposed to accommodate a carrier for the semiconductor device into a tightly shield box for realizing the automation. This is disclosed in Japanese laid-open utility model publication No. 59-83038. This method, however, provides a problem with complicated operations of the box so that the yield is dropped. Further, a long time accommodation of the carrier for the semiconductor wafer into the box causes another problem with generation of gas from the semiconductor wafer so that the box is filled with the gas, whereby the characteristics of the semiconductor wafer might be changed.
In the above circumstances, it has been required to improve the productivity of the semiconductor devices and to develop a high performance dust removing apparatus for removal of dusts as many as possible to reduce the probability of the adhesion of the dust on the semiconductor wafer. Except when the maintenance and the trouble shooting are carried out by person along with exposure of the semiconductor wafer to atmosphere including dusts, the semiconductor wafer is accommodated in a tightly shielding box for certain isolation of the semiconductor wafer from the atmosphere.
The descriptions will focus on a conventional method of transferring the carrier for semiconductor wafer to another transfer table with reference to FIGS. 1A and 1B. FIG. 1A is a view illustrative of a conventional carrier transfer system before transferring the carrier for semiconductor wafers from a first transfer table to a second transfer table involved in a conventional transfer method. FIG. 1B is a view illustrative of a conventional carrier transfer system after having transferred the carrier for semiconductor wafers from the first transfer table to the second transfer table involved in the conventional transfer method A conventional carrier transfer system is to transfer a carrier 40 for semiconductor wafers 60 from a first transfer table 61 to a second transfer table 62. A box transfer device 63 is provided over the first transfer table 61. An opening and closing transfer system 64 is provided over the second transfer table 62. The opening and closing transfer system 64 has a carrier transfer device 66 positioned over the second transfer table 62 and an adsorber 65 positioned over the second transfer table 62. A box 50 is placed on the first transfer table 61. A carrier 40 for mounting a plurality of semiconductor wafers 60 is accommodated in the box 50. The carrier 40 has a carrier flange 41 for allowing the carrier transfer device 66 to catch the carrier flange 41. The box 50 comprises a box body 51 and a box cap 52 for sealing the carrier 40 in the box from atmosphere The box 50 also has a box flange 53 for allowing the box transfer device 63 to catch the box flange 53. The box cap 52 is removed from or capped onto the box body 51 by the adsorber 65.
For carrier unloading operation, the box transfer device 63 is operated to move down to a lower level than the box flange 53 of the box 50 so that the box transfer device 63 is closed to catch the box flange 53 for rifting the box 50 up from the first transfer table 61. The box transfer device 63 is then moved toward the second transfer table 62, before the box transfer device 63 is fallen so that the box 50 is placed onto the second transfer table 62. The box transfer device 63 is opened to release the box 50. The box transfer device 63 is moved back to the original position over the first transfer table 61. In place, the opening and closing transfer system 64 is operated to move to a position over the box 50 placed on the second transfer table 62. The adsorber 65 is made into adsorption with the box cap 52 before the adsorber 65 is moved upwardly so as to rift the box cap 52 up from the box body 51, whereby the box cap 52 is opened. The carrier transfer device 66 is operated to move down to a lower level than the carrier flange 41 of the carrier 40 so that the carrier transfer device 66 is closed to catch the carrier flange 41 for rifting the carrier 40 up from the box 50. The carrier transfer device 66 is then moved toward other position than the box 50 but over the second transfer table 62, before the carrier transfer device 66 is fallen so that the carrier 40 is placed onto the other position than the box 50 but on the second transfer table 62. The box transfer device 63 over the original position over the first transfer table 61 is moved to a position over the second transfer table 62. The carrier transfer device 66 is opened to release the carrier 40. The box transfer device 63 is operated to move down to a lower level than the box flange 53 of the box 50 on the second transfer table 62 and concurrently the adsorber 65 with the box cap 52 is moved down onto the box 50 so that the box cap 52 is placed on the box body 51 of the box 50 before the adsorber 65 comes free of adsorption with the box cap 52 to release the box cap 52 from the adsorber 65, whereby the box cap 52 is capped on the box body 51 of the box 50. The adsorber 65 is moved upwardly to back to the original position over the second transfer table 62. Also the carrier transfer device 66 is moved upwardly to back to the original position over the second transfer table 62. Further, the box transfer device 63 is closed to catch the box flange 53 for rifting the box 50 up from the second transfer table 62. The box transfer device 63 is then moved from the second transfer table 62 toward the first transfer table 61, before the box transfer device 63 is fallen so that the box 50 is transferred back onto the first transfer table 61. The box transfer device 63 is opened to release the box 50 on the first transfer table 61. The box transfer device 63 is moved back to the original position over the first transfer table 61.
For carrier loading operation, the box transfer device 63 is operated to move down to a lower level than the box flange 53 of the box 50 so that the box transfer device 63 is closed to catch the box flange 53 for rifting the box 50 up from the first transfer table 61. The box transfer device 63 is then moved toward the second transfer table 62, before the box transfer device 63 is fallen so that the box 50 is placed onto other position than the carrier 40 on the second transfer table 62. The box transfer device 63 is opened to release the box 50. The box transfer device 63 is moved back to the original position over the first transfer table 61. In place, the opening and closing transfer system 64 is operated to move to a position over the box 50 placed on the second transfer table 62. The adsorber 65 is made into adsorption with the box cap 52 before the adsorber 65 is moved upwardly so as to rift the box cap 52 up from the box body 51, whereby the box cap 52 is opened. The carrier transfer device 66 is operated to move down to a lower level than the carrier flange 41 of the carrier 40 so that the carrier transfer device 66 is closed to catch the carrier flange 41 for rifting the carrier 40 up from the second transfer table 62. The carrier transfer device 66 is then moved toward a position over the box 50 on the second transfer table 62, before the carrier transfer device 66 is fallen onto the box 50 on the second transfer table 62, so that the carrier 40 is placed into the box body 51 of the box 50, whereby the carrier 40 is accommodated within the box body 51. The adsorber 65 with the box cap 52 is moved down onto the box 50 so that the box cap 52 is placed on the box body 51 of the box 50 before the adsorber 65 comes free of adsorption with the box cap 52 to release the box cap 52 from the adsorber 65, whereby the box cap 52 is capped on the box body 51 of the box 50. The adsorber 65 is moved upwardly to back to the original position over the second transfer table 62. Also the carrier transfer device 66 is moved upwardly to back to the original position over the second transfer table 62. The box transfer device 63 over the original position over the first transfer table 61 is moved to a position over the second transfer table 62. The box transfer device 63 is operated to move down to a lower level than the box flange 53 of the box 50 on the second transfer table 62. Further, the box transfer device 63 is closed to catch the box flange 53 for rifting the box 50 up from the second transfer table 62. The box transfer device 63 is then moved from the second transfer table 62 toward the first transfer table 61, before the box transfer device 63 is fallen so that the box 50 is moved onto the first transfer table 61. The box transfer device 63 is opened to release the box 50 on the first transfer table 61. The box transfer device 63 is moved back to the original position over the first transfer table 61.
FIG. 2 is a schematic perspective view illustrative of a conventional production line utilizing the above conventional carrier transfer system of FIGS. 1A and 1B. The conventional production line has a plurality of manufacturing equipments 71, a plurality of automatic carrier trucks 73, and an automatic rack 72. Each of the automatic carrier trucks 73 has a loading surface 76 for carrying the box 50 accommodating the carrier 40 for carrying a plurality of the semiconductor wafers 60. Each of the manufacturing equipments 71 has an entrance 74 which is provided with the opening and closing transfer system 64. The automatic rack 72 also has an entrance 75 which is provided with the opening and closing transfer system 64. Each of the automatic carrier trucks 73 has the box transfer device 63. The loading surface 76 of the automatic carrier truck 73 in FIG. 2 corresponds to the first transfer table 61 in FIGS. 1A and 1B. The entrance 74 of the manufacturing equipment 71 and the entrance 75 of the automatic rack 72 in FIG. 2 correspond to the second transfer table 62 in FIGS. 1A and 1B. The carrier loading and unloading operations between the loading surface 76 of the automatic carrier truck 73 and the entrances 74 and 75 are accomplished as described above with reference to FIGS. 1A and 1B.
The above conventional carrier transfer system has the following four disadvantages. The first disadvantage of the conventional carrier transfer system is that it takes a long time to carry the carrier and loading or unloading the carrier because it is necessary to open and close the box cap of the box and carry the box free of the carrier.
The second disadvantage is that an additional space for installation of the opening and closing transfer system having the carrier transfer device separately from the box transfer device.
The third disadvantage is that it is necessary to provide the opening and closing transfer systems for every manufacturing equipments, for which reason the production systems is expensive, resulting in the increased manufacturing cost. Further, a huge cost is necessary to improve the production system.
The fourth disadvantage is that a gas is generated from the semiconductor wafers so that the sealed box is filled with the gas, whereby the gas may provide influences to the characteristic of the semiconductor wafers due to a long time exposure of the semiconductor wafers to the generated gas.
In the above circumstances, it had been required to develop a novel semiconductor wafer accommodating jig, handling method and production system free from the above disadvantages.